spanification: Add #pragma allow_unsafe_buffers to ipc/*

This is a preparation to fix each files.
This CL has no behavior changes.

This patch was fully automated using script:
https://paste.googleplex.com/5614491201175552

Note that in patchset2, change to:
/build/config/unsafe_buffers_paths.txt
was reverted. Indeed, running too many (~3) CQ run touching this file is
making the builder cache much slower. I will bundle every change to this
file in a subsequent CL. I will limit myself to 1-2 CQ run per day.

See internal doc about it:
https://docs.google.com/document/d/1erdcokeh6rfBqs_h0drHqSLtbDbB61j7j3O2Pz8NH78/edit?resourcekey=0-hNe6w1hYAYyVXGEpWI7HVA&tab=t.0

Bug: 351564777
Change-Id: Ibb92af9382433c7518d8e8ac11b73361832c589f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5718051
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Auto-Submit: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1329707}

ipc/ipc_channel_reader.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_channel_reader.h"
 
 #include <stddef.h>

ipc/ipc_message.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_message.h"
 
 #include <limits.h>

ipc/ipc_message_pipe_reader.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_message_pipe_reader.h"
 
 #include <stdint.h>

ipc/ipc_message_protobuf_utils_unittest.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "build/build_config.h"
 
 #include "ipc/ipc_message_protobuf_utils.h"

ipc/ipc_message_unittest.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_message.h"
 
 #include <stddef.h>

ipc/ipc_message_utils.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_message_utils.h"
 
 #include <stddef.h>

ipc/ipc_mojo_bootstrap_unittest.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_mojo_bootstrap.h"
 
 #include <cstdint>

ipc/ipc_perftest_util.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_perftest_util.h"
 
 #include <tuple>

ipc/ipc_test_channel_listener.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/ipc_test_channel_listener.h"
 
 #include "base/run_loop.h"

ipc/message_filter_router.cc

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifdef UNSAFE_BUFFERS_BUILD
+// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
+#pragma allow_unsafe_buffers
+#endif
+
 #include "ipc/message_filter_router.h"
 
 #include <stddef.h>